This invention relates to audio signalling devices, generally referred to as buzzers, having use, for example, in automobiles to signal a warning to the driver when he opens the front door of the automobile without removing his keys from the ignition and to signal at least a temporary warning when the driver of the automobile fails to connect his seat belt. In the past, these two types of buzzers were mounted in completely separate housings, in turn, mounted in separate receiving sockets attached to connecting harnesses. The present invention combines these two types of buzzer units in a common housing assembly and in a manner which minimizes the cost of manufacture thereof and reduces the overall size of the buzzer assembly.